A soft water monitoring apparatus is used to monitor a soft water flow as to the hardness thereof and to protect the user of the soft water from excessively high water hardness. Some applications include steam boilers and reverse osmosis systems, evaporators and distillation systems. The system enables continuous monitoring.
A partial flow of the soft water is conducted through a hardness measuring cell during soft water monitoring. If hard water flows through the hardness measuring cell, the measurement filling in the hardness measuring cell is depleted and the volume thereof changes and shrinks. This causes an electrical signal to be triggered and a controller reports an alarm, which can be used to deactivate devices.
If the soft water supply is restored, the hardness measuring cell must be regenerated. Valves installed for this purpose over the measuring distance must be actuated and the measuring distance is disconnected in this way from the main flow. A small amount of brine is injected into the hardness measuring cell. The hardness measuring cell is then rinsed with soft water. This procedure lasts a total of 3 to 5 minutes. Hardness measuring cells are known, for example, from DE 34 06 724 C2 and from EP 0 016 408 A1. This process is carried out manually, which is not only laborious, but also time consuming.